In the semiconductor manufacturing industry various types of chemical processes (e.g., chemical vapor deposition) are used to manufacture integrated circuits and other devices. Some of the chemical processes that are used may generate undesirable chemical pollutants that contaminate the environment. It is very important that the creation of these chemical pollutants be controlled and that these chemical pollutants not be allowed to escape into the environment.
Abatement methods have been developed to minimize or eliminate the creation of these hazardous pollutants and prevent them from being released into the atmosphere. The exhaust gases from a chemical process are typically processed in a reactor chamber in order to trap and remove the pollutants from the exhaust gases. Some well known pollutants are tetraethyloxysilane (TEOS), silane (SiH4) and tungsten (W).
For example, a reactor chamber that removes tungsten dust from an exhaust gas operates by heating the exhaust gas and by reacting the heated exhaust gas with water. The tungsten particles that are removed from the exhaust gas collect on the interior walls of the reactor chamber. Other types of chemical processes are used for different types of pollutants.
The reactor chamber in a pump exhaust abatement system must be periodically cleaned in order to perform properly. Over time the pollutant that is trapped by the reactor chamber (e.g., tungsten) will accumulate and diminish the efficiency of the reactor chamber. Therefore the accumulated pollutants must be periodically removed from the reactor chamber. A prior art method for cleaning a reactor chamber will now be described with reference to FIG. 1 and FIG. 2.
FIG. 1 illustrates an external view of a prior art cabinet 100 that contains a prior art reactor chamber (not shown in FIG. 1). The cabinet 100 is placed on a base 120. Cabinet vents 130 are provided through side walls of the cabinet to allow air from the ambient atmosphere to reach the interior of the cabinet 100. A cabinet exhaust port 140 through the top of the cabinet 100 is also provided. A pump (not shown) that is connected to the cabinet exhaust port 140 removes air from the interior of the cabinet 100 when the reactor chamber is operating to create a reduction in atmospheric pressure within the interior of the cabinet 100. This reduction in atmospheric pressure within the interior of the cabinet 100 tends to keep any pollutants that may escape from the reactor chamber within the cabinet 100.
Access to the interior of the cabinet 100 is through a door 150 through a side wall of the cabinet 100. An abatement inlet 160 through the top of the cabinet 100 provides a flow of exhaust gas to the reactor chamber 210 (shown in FIG. 2).
FIG. 2 illustrates an interior view of the cabinet 100 in which the door 150 is open. The reactor chamber 210 receives a flow of exhaust gases from the abatement inlet 160. The reactor chamber 210 operates to remove the pollutant (e.g., tungsten) from the flow of exhaust gases as previously described. The flow of exhaust gases leaves the reactor chamber 210 through an abatement outlet (not shown in FIG. 2) through a wall of the cabinet 100.
When it is time to clean the reactor chamber 210 a technician who performs a prior art cleaning method must put on personal protective gear. The protective gear is necessary because of the toxic and dangerous nature of the pollutant that has been accumulated in the reactor chamber 210. The protective gear generally must include gloves, an apron, and a breathing mask with a self contained source of breathable air from an air tank. Due to safety regulations a second person must also be present during the cleaning operation because the cleaning technician is using a breathing mask and self contained breathing equipment.
The technician opens the door 150 and disconnects the reactor chamber 210 from the abatement outlet (not shown) and removes a bottom flange (not shown) from the reactor chamber 210. The technician then removes the accumulated pollutant from the reactor chamber. For example, in the case of removing tungsten from the reactor chamber, the technician scrapes the interior walls of the reactor chamber 210 and places tungsten debris into a bag for subsequent removal. This method causes tungsten dust to spill out into the environment around the cabinet 100.
After the reactor chamber 210 has been cleaned, the technician removes the bag with the accumulated tungsten, replaces the bottom flange on the reactor chamber 210 and reconnects the reactor chamber to the abatement outlet. The technician then closes the door 150 of the cabinet 100. The reactor chamber 210 is then ready to go back into operation. This prior art method unavoidably releases some tungsten dust into the environment.
Therefore, there is a need in the art for a system and method that is capable of providing an improved method for cleaning a reactor chamber of a pump exhaust abatement system. There is a need in the art for a system and method that is capable of cleaning a reactor chamber of a pump exhaust abatement system while minimizing the release of pollutants into the environment.